Confirmed and as wiki page mentions, this could happen with small objects. However why would you want to use attachTo? This is Arma 3 and lantern is PhysX object. If you just place it over the table

latern1 setpos (table1 modelToWorld [0,0,0.6]);

You can observe it falls and stays on top of the table and if you shoot it, it falls over, isn't this a better solution?

@KillZone Kid:

Sadly this doesn't work so well, the lantern will be stuck in the middle of the table board and some objects like dossiers just completely fall through it.

@Helio This is not true. I have just placed a file on camping table with setPos. It is tricky as if you put it a bit higher or lower it falls through. But there there is Z number which will make it stay. If you shoot it it will fall through.

If you use attachto it doesnt move the file but it does attach it (returned attachedTo array is not empty). Any attached object has simulation disabled, so what you can do is place object with setpos and disable its simulation:

file1 setpos (table1 modeltoworld [0.2,0,0.41]);
file1 enablesimulation false;

Attchto does seem to be messed up. Using small objects I get the following

file1 setpos (table1 modeltoworld [0.2,0,0.41]);file1 attachto [table1];

Will also set the files without it falling however if you move the table the object is left behind.

Also if I use the following nothing happens (small objects file)

null=[] spawn {sleep 1;file1 attachto [desk,[0,0,0.56]]};

But if you change sleep 1 to sleep 0.01 the file now moves to the desk.

If you use files from Intel then the delay doesn't matter.

There is no consistency with object in this game. Attched should attach them not position them and whats with the delay?

Probably related to http://feedback.arma3.com/view.php?id=7228

@f2k sel As a workaround you can try to add "EpeContact" event handler to the table and cycle through attachedObjects and reposition them every time when table is disturbed

That can work but it is still only a work around, I use an invisible helper object or game logic and attach small objects to that and then just move the helper with the main object. It's not ideal but they are actually attached.
A sort of virtual object holder.

It's strange that you can attach objects to helpers , grave items, game logics and vehicles but not desks, tables and shelves.